Process for treating continuous filaments

ABSTRACT

Process and apparatus are described for washing a tow of continuous filaments, such as protein fibers, wherein the tow and a treating liquid, such as an alkaline solution or water, are concurrently passed longitudinally along a conduit and several fluid streams, such as air streams, are passed transversely through the tow to agitate the filaments and enable the treating liquid to contact all the filaments.

United States Patent Boyer et a1.

PROCESS FOR TREATING CONTINUOUS FILAMENTS Inventors: Robert Allan Boyer;Anthony Hing Chen, both of Columbus, Ohio Miles Laboratories, Inc.,Elkhart, Ind.

Filed: Mar. 19, 1973 Appl. No.: 342,731

Assignee:

US. Cl 8/139, 8/151, 68/163 Int. Cl D061 l/12 Field of Search 8/139,151; 68/183 References Cited UNITED STATES PATENTS 12/1964 Oshan 8/1513,159,017 12/1964 Oshan 23/151 Primary Examiner-Mayer Weinblatt [57]ABSTRACT Process and apparatus are described for washing a tow ofcontinuous filaments, such as protein fibers, wherein the tow and atreating liquid, such as an alkaline solution or water, are concurrentlypassed longitudinally along a conduit and several fluid streams, such asair streams, are passedtransversely through the tow to agitate thefilaments and enable the treating liquid to contact all the filaments.

8 Claims, 2 Drawing Figures PROCESS FOR TREATING CONTINUOUS FILAMENTSBACKGROUND AND PRIOR ART It has been known for several years thatcontinuous filaments, such'as proteinaceous fibers, can be prepared byextruding an alkaline solution of protein, such as casein or soyprotein, through a plurality of small openings into an acid bath wherebythe extrudate is coagulated into a tow of protein fibers. One use forsuch fibers is in the production of textured food products. U.S. Pat.No. 2,682,466 describes the combination'of spun protein fibers andedible binders to form textured protein food products, such as simulatedmeats.

The as-spun protein fibers have an acidic pH value below about 4, forexample, and thus are not directly suitable in simulated meats. It isknown that the spun fibers can be treated with a neutralizing bath, suchas an aqueous sodium bicarbonate and sodium chloride solution, to adjusttheir pH to a more desirable value between about 4 and 7. Theneutralized fibers are then washed with water to remove the saltsresulting from the neutralization step. The prior art techniquesandapparatus for adjusting the pH of protein fibers, such as that describedin U.S. Pat. Nos. 3,269,841; 3,3l4,356; 3,403,027; 3,554,] 13; and3,677,038, were undesirably complex and did not produce a completelysatisfactory product. Similar problems exist when attempts have beenmade to treat other continuous filaments.

SUMMARY OF THE INVENTION DESCRIPTION OF THE DRAWINGS FIG. 1 is a sideelevational view, partially broken away, of one form of apparatussuitable for carrying out the process of the present invention; and

FIG. 2 is a side elevational view of another form of apparatus suitablefor carrying out the process of the present invention.

DESCRIPTION OF THE INVENTION FIG. 1 shows apparatus consisting of anelongated conduit having an entrance mouth 12 and an exit 14. Conduit 10is located in a substantially horizontal position, but it may be tippedslightly downward toward exit 14 if this is desired. A plurality ofspaced vertical inlet pipes 16, each having an outlet 18 whichcommunicates with the interior of conduit 10, are located longitudinallyalong the bottom 20 of conduit 10. Inlet pipes 16 all are incommunication with a supply pipe 22 which has an inlet 23. A collector24 having an open mouth 26 is located beneath the outlet of exit 14 ofconduit 10. Collector 24 communicates with a pipe 28 which, in turn,communicates with a pipe 30. Pipe 30 is in communication with conduit 10near inlet 12 and has its own inlet 32. A pump 34 is located in pipe28.

In the operation of the process of the present invention, a treatingliquid 36, such as an alkaline neutralizing solution or a water wash, isintroduced from a supply source (not shown) through the inlet 32 andpipe 30 into conduit 10. The treating liquid 36 leaving conduit 10through exit 14 is collected by collector 24, is recycled by pump-34through pipe 28 and is combined with fresh treating liquid 36 in pipe 30for introduction into conduit 10.

A tow of continuous filaments 38, such as protein fi-. bers, obtainedfrom a previous processing step (not shown) is introduced to conduit 10through inlet 12. Sufficient liquid 36 is introduced to maintain conduit10 substantially full. The tow 38 is immersed in the treating liquid 36and is concurrently passed with the treating liquid longitudinally andsubstantially horizontally along conduit 10. The flow of the treatingliquid from pipe 30 to the exit 14 of conduit 10 acts as a conveyor forthe tow 38.

A fluid 40 is introduced from a supply source (not shown) through theinlet 23 of pipe 22 and then through the plurality of pipes 16. Thisfluid 40 forms a plurality of fluid streams which simultaneously passupwardly and substantially vertically transversely through the tow ofprotein fibers 38 to agitate and separate the fibers and enable thetreating liquid to contact all the fibers. Fluid 40 is preferablygaseous, such as air or any other gas which does not adversely reactwith the treat ing liquid or the tow. Fluid 40 could also be anotherliquid, such as the treating liquid, or a mixture of gas and liquid.Gaseous fluid 40 leaves conduit 10 through exit 14 and mixes with theambient atmosphere.

The tow 38 leaving the conduit 10 through exit 14 can then be used assuch in the production of endproducts, such as textured proteinproducts, or it can be processed further as desired.

As discussed above, an acidic tow of protein fibers originally producedby coagulation of the proteinaceous raw material should be neutralizedand then washed with water to remove the salts due to theneutralization. This is conveniently accomplished by the apparatus shownin FIG. 2. The elements of the twostage apparatus of FIG. 2 have thesame identifying numbers with the suffix a for the first. stage and thesuffix .b for the second stage. The operation of the individual stagesof FIG. 2 are the same as the operation of the single stage of FIG. 1.

The acidic tow 38a enters conduit 10a while treating liquid 36a, such asa neutralizing solution, concurrently flows through conduit 10a. Fluid40a, such as air, passes upwardly transversely from pipes 16a throughconduit 10a and agitates and separates the fibers of tow 38a.

As tow 38a exits from conduit 10a, .it passes over guide rollers 42 and44 and enters inlet 12b of conduit 10b as tow 38b. Guide rollers 42 and44 can be motor driven by means not shown, if desired, to assist inconveying tow 38a from conduit 10a to conduit 10b. Treat ing liquid 36b,such as water, concurrently flows through conduit 10b along with tow38b. Fluid 4012, such as air, passes upwardly transversely from pipes16b through conduit 10b and agitates and separates the fibers of tow38b. The number and size of the pipes 16b can be the same, greater, orless than the number and size of the pipes 16a as desired or-necessaryfor proper operation.

The tow 38b leaving conduit b can be squeezed by rollers 46 and 48,adjusted and driven by means not shown, to remove liquid adhering to andabsorbed by the fibers, if desired. The resulting tow can be useddirectly in subsequent processing.

The process and apparatus described above introduced the plurality ofagitating fluid streams along the bottom of the horizontal conduit sothat such streams flowed vertically upward through the tow. Itisunderstood that the scope of the present invention also includes theprocess and apparatus wherein the plurality of agitating fluid streamsare introduced along the top or the sides of the horizontal conduit. Inthis way such fluid streams still flow transversely through the tow.

The invention is described in further detail in the following example.

EXAMPLE Four tows of acid protein fibers were produced by passing analkaline solution of soy protein through four spinnettes, each having15,000 holes (0.004 in. dia.), and the resulting extrudates werecoagulat ed at room temperature in an acidic aqueous solution containing2-5 weight percent phosphoric acid and 7-l0 weight percent sodiumchloride and having a pH of 0.7-1.1. The resulting tows having a pH of2.2 were then passed through another acidic aqueous solution having theabove composition at a temperature of 200F. (93C.) for 5-6 seconds. Thefour acidic tows were then combined into one tow of continuousfilamentsand passed at a linear velocity of 33 ft./min. into a single horizontal6 in. dia. pipe ft. long through which an aqueous alkaline solutioncontaining 0.8 weight percent sodium bicarbonate and 8 weight percentsodium chloride was also concurrently passed at a flow rate of 20 gpm. Aseries of 45 /4 in. dia. pipes each having a l /l 6 in. dia. outletnozzle were longitudinally located along the bottom of the above 6 in.dia. pipe in three rows of 15 pipes each in which the pipes in each rowwere substantially equally spaced along the length of the longitudinalpipe. A total of 50 cu. ft. per min. of air was passed upwardly andtransversely from these'pipes through the tow to agitate and separatethe fibers. The tow leaving this neutralizing stage contained 4.2 weightpercent sodium chloride and had a pH of 6.0. It was separated from theneutralizing solution which was then recycled through the neutralizingstage. The tow then passed over a pair of transferring rollers andentered another single horizontal 6 in. diaQpipe 45 ft. long through Theprocess and apparatus of the present invention have the advantages overthe prior art of 1) improved agitation with more complete neutralizationand rinsing and (2) less complex apparatus. The tow is conveyed throughthe processing stations by the concurrent treating solution flow and theagitation means requires no which water was also concurrently passed ata flow rate of 15 gpm. A series of 68% in. dia. pipes each with a l/l6in. dia. outlet nozzle were longitudinally located along the bottom ofthe above 6 in. dia. in three rows of 23, 23 and 22 pipes, respectively,in which the pipes in each row were substantially equally spaced alongthe length of the longitudinal pipe. A total of 40 cu. ft. per min. ofair was passed upwardly and transversely from these pipes through thetow to agitate and separate the fibers. The tow leaving the rinsingstage was separated from the rinsing solution which was then recycledthrough the rinsing stage. The tow was then dewatered by passing througha pair of squeezing rollers and cut into desired length for productusage. The tow product contained 80 weight percent moisture, 1 weightpercent sodium chloride and had a pH of 6.0.

moving parts.

The dimensions of the apparatus, the number of stages and the flow ratesof the reactants are not critical and will be dependent upon the sizeand speed of the.

tow and the treating specifications, such as the neutralization andrinsing specifications.

While the above description has been directed primarily atneutralization and rinsing of soy protein fibers, it is understood thatthe process and apparatus of the present invention is also applicablefor the addition of flavoring and other ingredients to such proteinfibers and for the treatment of other continuous filaments, such asedible alginate andcasein fibers and various textile filaments;

What is claimed is:

1. A process for treating a tow of continuous protein filaments with atreating liquid which comprises immersing the tow of continuous proteinfilaments in the treating liquid and concurrently passing the tow ofcontinuous protein filaments and the treating liquid longitudinally andsubstantially horizontally along a conduitgaseous, said gaseous fluidbeing a gas which does not adversely react with the treating liquid orthe tow of protein filaments.

3. A process according to claim 1 wherein the treating liquid isrecycled for reuse in concurrent flow.

4. A process according to claim 1 wherein the plurality of fluid streamsare passed upwardly through the tow. p i

5. A process according to claim 1 wherein the tow of continuous proteinfilaments is separated from a first treating liquid as it exits from afirst conduit and is sub sequently treated a second time by immersingthe tow of continuous protein filaments in a second treating liquid andconcurrently passing the tow of continuous protein filaments and thesecond treating liquid longitudinally and substantially horizontallyalong a second conduit while simultaneously passing a second pluralityof fluid streams transversely through the tow of continuous proteinfilaments to agitate the protein filaments and enable the secondtreating liquid to contact all the protein filaments, the amount andflow rate of said second treating liquid being such as to completelycover the protein filaments.

6. A process according to claim 5 wherein the various plurality of fluidstreams which are passed transversely 3,854,870 6 7. A process accordingto claim 5 wherein the first treating liquid is an alkaline neutralizingsolution, the treating liquid is different in composition from thesecsecond treating liquid is water and the various plurality ondtreating liquid. of fluid streams are air.

8. A process according to claim 5 wherein the first

1. A PROCESS FOR TREATING A TOW OF CONTINUOUS PROTEIN FILAMENTS WITH ATREATING LIQUID WHICH COMPRISES IMMERSING THE TOW OF CONTINUOUS PROTEINFILAMENTS IN THE TREATING LIQUID AND CONCURRENTLY PASSING THE TOW OFCONTINUOUS PROTEIN FILAMENTS AND THE TREATING LIQUID LONGITUDINALLY ANDSUBSTANTIALLY HORIZONTALLY ALONG A CONDUIT WHILE SIMULTANEOUSLY PASSINGA PLURALITY OF FLUID STREAMS TRANSVERSELY THROUGH THE TOW OF CONTINUOUSPROTEIN FILAMENTS TO AGITATE THE PROTEIN FILAMENTS AND ENABLE THETREATING LIQUID TO CONTACT ALL THE PROTEIN FILAMENTS, THE AMOUNT ANDFLOW RATE OF SAID TREATING LIQUID BEING SUCH AS TO COMPLETELY COVER THEPROTEIN FILAMENTS.
 2. A process according to claim 1 wherein theplurality of fluid streams which are passed transversely through the towof continuous protein filaments are gaseous, said gaseous fluid being agas which does not adversely react with the treating liquid or the towof protein filaments.
 3. A process according to claim 1 wherein thetreating liquid is recycled for reuse in concurrent flow.
 4. A processaccording to claim 1 wherein the plurality of fluid streams are passedupwardly through the tow.
 5. A process according to claim 1 wherein thetow of continuous protein filaments is separated from a first treatingliquid as it exits from a first conduit and is subsequently treated asecond time by immersing the tow of continuous protein filaments in asecond treating liquid and concurrently passing the tow of continuousprotein filaments and the second treating liquid longitudinally andsubstantially horizontally along a second conduit while simultaneouslypassing a second plurality of fluid streams transversely through the towof continuous protein filaments to agitate the protein filaments andenable the second treating liquid to contact all the protein filaments,the amount and flow rate of said second treating liquid being such as tocompletely cover the protein filaments.
 6. A process according to claim5 wherein the various plurality of fluid streams which are passedtransversely through the tow of continuous protein filaments aregaseous, said gaseous fluids being of gases which do not adversely reactwith the treating liquids or the tow of protein filaments.
 7. A processaccording to claim 5 wherein the first treating liquid is different incomposition from the second treating liquid.
 8. A process according toclaim 5 wherein the first treating liquid is an alkaline neutralizingsolution, the second treating liquid is water and the various pluralityof fluid streams are air.